Stereotactic cervical myelotomy.

Abstract

The first spinal commissurotomy was performed by Armour and reported in 1927. The patient, suffering from tabetic gastric pain, died post-operatively. Putnam (1934) devised a similar procedure independently and advocated it for intractable pain in the arms and shoulders. The operation aimed at interrupting the decussating fibres passing to the spinothalamic tracts and, since the decussation was believed to take place over two to three segments for each dermatome, an attempt was made to split the commissure over several segments. Putnam's first patient was completely relieved of pain, and analgesia was produced from C5 to approximately T9 by splitting the commissure from C4 to T3, subsequently confirmed at necropsy. His second patient had only incomplete relief and a third patient died post-operatively. The method soon fell into disrepute because of cases of paralysis caused by injury to the anterior spinal artery. Leriche performed commissurotomy at lower levels in 1928 and reported it in 1936. It is now an established pain-relieving procedure, notably by French workers.Theoretically, cervical commissurotomy would be ideal for bilateral shoulder, arm, or upper chest pain which is uncommon. Unilateral arm or chest pain due to bronchial carcinoma, however, is relatively common and, although such pain can be relieved by high cervical cordotomy, pre-operative respiratory inadequacy may make the procedure hazardous due to injury to descending respiratory pathways (Belmusto, Brown, and Owens, 1963; Hitchcock and Leece, 1967). The advantages of a procedure which would not interfere with these pathways encouraged a reappraisal of the operation of cervical commissurotomy.The extensive laminectomy and myelotomy required, with the risk of injury to the anterior spinal artery, seemed to demand the use of a more precise method. Percutaneous stereotactic spinal tractotomy had been described, using a special stereotactic instrument (Hitchcock, 1969), and a similar technique has been used to interrupt the spinal commissure at the first cervical segment or cervico-medullary junction. MATERIAL AND METHODPatients with intractable pain due to advanced malignant disease were offered this procedure after conservative methods had failed.The patient was seated in the upright posture with the head moderately flexed on the neck and the stereotactic frame applied. The midline of the cord was assumed to lie in the midline of the odontoid process and spinal canal. A posterior-anterior radiograph was taken to determine the offset of the frame in respect of the midline and to enable necessary corrections of the electrode carrier.A lateral view was then taken, again using the odontoid as a bony landmark and assuming that, with the head in the mildly flexed position, the anterior surface of the cord was approximately.2 to 3 mm behind the odontoid line and the thickness of the cord was 10 mm. The cord equator was marked on the film and a suitable point chosen along it to permit the entry of an electrode by direct percutaneous track through the ...

Commissural Myelotomy in the Treatment of Intractable Visceral Pain: Technique and Outcomes

“…Surgical interventions for the management of visceral pain have focused on interrupting either commissural fibers associated with the anterolateral system, midline fibers associated with the visceral pain pathways, or both [10][11][12] . Various surgical techniques have been proposed for performing a myelotomy for pain control, including open midline myelotomy, stereotactic percutaneous myelotomy, CT-guided percutaneous myelotomy and punctate midline myelotomy [5,7,18,19] .…”

“…Various surgical techniques have been proposed for performing a myelotomy for pain control, including open midline myelotomy, stereotactic percutaneous myelotomy, CT-guided percutaneous myelotomy and punctate midline myelotomy [5,7,18,19] . The midline commissural myelotomy was introduced by Armour in 1927, and in 1968 Hitchcock performed the first stereotactic percutaneous myelotomy [4,10] . With Hitchcock's approach, the patient was seated with the head flexed within a stereotactic headframe.…”

“…With this observation, it was proposed that the pain relief mechanism might relate to an extralemniscal ascending pain system [5,[7][8][9] . Thus, punctate or limited myelotomy aimed at interrupting that system has been advocated by some, while others favor myelotomy aimed at interrupting commissural fibers over several levels of the cord [10][11][12] . Candidates for midline myelotomy include patients with intractable pain associated with malignancy in the abdominal or pelvic region.…”

Myelotomy through the Years

“…This led Hitchcock [4], in 1970, to report relief of pain throughout the body with a limited lesion made stereotactically in the center of the spinal cord at the C1 level, which was possible with his stereotactic apparatus that permitted an approach to the foramen magnum with the patient in the sitting position. Although the name belied the anatomical observation, he referred to his procedure as 'commissural myelotomy'.…”

Respiratory Changes after Stereotactic High Cervical Cord Lesions for Pain

“…All patients were suffering from severe pain intractable to opiates. Patients with unilateral, or mainly unilateral, pain in the trunk or extremities had a cordotomy, while patients suffering from bilateral or pain in multiple sites were chosen for myelot omy or commissurotomy [6]. Trigeminal tractotomies were carried out in patients suffer ing from unilateral facial pain.…”